OBJECTIVES: 1. Comparison of RPC-5 chromatographic properties of tRNAs isolated from human liver and correspondent neoplastic tissues. 2. Purification of those pairs of tRNA, normal and their neoplastic counterpart, which show significant chromatographic differences and 3. Analysis of the sequence and modified nucleotide content of these tRNAs. 4. Similar work listed in 1, 2, and 3 on tRNA from 3T3 cells and 3T12 cells.